You're right, bicycles do belong on the street -- it's actually safer for them there (most accidents are at intersections, and the closer you are to the middle of the road, the more visible you are).

However, far worse than pedestrian ragers are car ragers. There's something about being isolated in a bubble that turns ordinary people into ragers. And some of these car ragers believe that bicycles belong on sidewalks and deliberately endanger bicyclist lives to force them onto the sidewalk.

There's no easy solution, but one is simply more bicyclists, making bicyclists a common site on roads.

That's a completely different matter, though, in that it's not permissible to ride a bike on a sidewalk pretty much anywhere (here, we must use the bike path although I'd prefer the street which is the case elsewhere). It's reasonable to be upset at people breaking codified behaviour (law, even) – similar to a pedestrian walking down the road instead of the sidewalk.

The intra-sidewalk issue of various pedestrians wandering around aimlessly, stopping randomly, walking inexplicably slowly &c. is the studied topic.

I must admit, I get quite frustrated with the above though not to the point of being angry let alone enraged. I've always imagined that city people are better at passively taking others into account when moving but that might make an interesting study as well.